Automatic shut-off device



May 8, 1928. 1,669,280

W. E. BLAIR ET Ax,

AUTOMATIC SHUT-OFF DEVICE Filed Oct. '7. 1925 @y @5% fm Patented May 8, 1928.

'n UNITED srATEsPATi-:NT oFFlcag.

WILLIAM E. BLAIR AND vALnNTNE D. KAUTH, or BUFFALO, NEW YORK.

AUTOMATIC SHUT-OFF DEVICE.

. Application led 0ctober.-7, 1925. Serial No. 61,103. i

This invention relates to an` .automatic shut-ofi' device which is more particularlyl designed for automatically shutting off the supply of gas or other fluid fuel toa gas engine when the same ceases to operate cit-,her when stopping the engine at will orwhen the same is stopped by reason of a cessation 'of fuel supply, failure of the ig-` nition system or other cause. At the present time the insurance.,underwriters require gas engines which are operated indoors to provide an automatic shutoff device of this character so thatcommunication between the gas inlet of the engine and the source of supply is positively cut-ofi' whenever the gas is stopped so that all liability of flooding the engine and the room in which the engine is installed is avoided, which otherwise might result in an accumulationof gas and an explosionand the same cause loss of property and personal injury. n

It is the object of this invention to provide an automatic shut-oft device for gas engines and similar installations, which can be readily set when starting the engine so as to permit proper flow of the `gaseous fuel from the source of supply to the inlet of the.

engine and whichV will be automatically held open so long as the engine is in operation but will vautomatically close the instant that the engine ceases to operate and can only be again restored toits operative condition by manually actuated means. j

The preferred organization which forms the subject of this invention whereby this result is accomplished, consists generally of a valve arranged in the conduit leading from the source of supply to the inlet of the gas engine, manually operated means whereby this valve may be opened to permit a flow of fuel from the source of supply to the engine, retaining means which hold the valve open and which are responsive to continuous pressure, such as a pressure ot' the lubri' eating system, and 'means i which effect an automatic yclosing of the valve when said ccn-` ktinuous pressure arrested, said closing means consisting preferably of a. spring which operates upon `said valve to hold the same yieldingly in its closed position. In the accompanyingV drawings Figure 1, is a side elevation, partly in section of an automatic shut-off device einbodyf` ing our invention, the sectional port-ion of this device being taken' on line 1-1, Fig. 2.

ing-.of this automatic shut-01T device which Y isV provided with an internal partition 11 which divi desthc same into an inlet chamber 12, having an inlet 13 which receives the combustible fluid such as gas or the like from any suitable source, and an outlet chamber 14 having an outlet 15 which is confnected by any suitable piping or conduit with the fuel inlet of the gas engine which is to be served, The partition, 11, is provided with a port 16, the upperend of which is provided `with an annular conical valve seat 17.4., This port isopened and closed rfor the purpose ofk either placing the inlet and outlet chambersf12 and 14 in communication withY each othery orinterrupting such communicae tion by means of` av conical valve 18 which is movable toward and fromthe rvalveseat 17 and the port in the partition 11, although other forms ofrvalves may be used. This valve is guided in its movement by means of a valve stem y19 projecting'downwardly from the under side of the valve .to the in; terior of the casing, and guided with its central partin aguideway20 on the lower part of the valve casing.

Means are provided whereby the valve may be opened manually preparatory 4to starting the operation of the engine, which means in their preferred form `as shown in the drawings, comprise a collar 2l secured to the central part of the valve stem v19 below the bottom ofthe valve casing, a bracket 22 depending from the under side of the valve casing and having" two arms 23, 23 arranged vertically on opposite sides of the ycentral part of the valve stem, a horizon- .having a salient face 26 which upon raising the cam is caused to. engage the under side `of the collar 21 and raise the same to such a position in-.Which the valve18 is lifted from its seat and alat tangentfface 27 which is adapted to engage theunder side of the eol-y lar 21 and become interlocked therewith so as to maintain the va'lve'18 in its open position, and a handle `or fingerpiece 28 project. inglaterally ,from the cani and adapted to hold the saine yielding'ly in this ,closed posi- Y tion, which closing means in the present instance preferably consistof a lo'wer'head` 29" arranged at the lower end of the arms 23, Ql and forining a partV of the bracket 22, and provided centrally with a guideway in which lthe central part of thel valve' stem slides, an abutment collar secured to the lower end of the valve stein, and a 'spring Blf surroundingr the lowei' partV of the valvev stein and bearing at its upper end against the under side of the bracket head Q9 and at itsV lower 'end against the collar 30V. The resilience of this spring 3l operates to draw the valve Vstem downwardly and inove the valve intoits closed position whenever the saine is free to do so and to yieldingly hold the same in this position.

ltfeaiis'are provided whereby the valve is held iii its open position so long as the engine is'in operation and the latter furnishes the necessary power for crea-ting a pressure which serves to hold the valve open butwhich permits this valve to close automatiu cally the instant that the engineceases to operate and, therefore, discontinues furnish-A ing` the necessary power for generating the pressure necessary for holding the valve open. The preferred means which are shown in the drawings for accomplishing this purpose are constructed as follows?- The numeral 32 represents a! cylinder which surrounds the lower end portion of the valve stein' and is closed at its upper end by the head 29 of the bracket 22 while its lowerend is closed by a headBS. Nithin this cylinder is arranged a cup-shaped piston 'twhich is adapted to Vslide vertically therein, the cylindrical wall 35 of this piston surrounding the lower part of the valve stein'andfthe spring 3l while the head 36 of this piston isarranged below the valve stem and is provided ,with a supporting teat or projection 37 adapt/edl to engage with the lower head 825 of' the'cylinder when the pistou is in lits lowerniost position. The space in lthe lowerend of the cylinderand below thevpistou therein vis'providedwith a pressureinlet 38 which is adapted to be con# nected by 'means of aconduit-39 with lany pressure source which is adapted to be gen` eratefdbv power derived from -the workiiiig' thel "engine Whi'cliis 'supplied by fuel i g lthrough thisicutsotf device.` This 'esourcepreferably consistsgof the pres lubrieatingy ysystem of"t li'e "gaslenginepofv which"V I' t hisffsliiitoif device fforiiis af "part, Lubricating systems 4of thisfjfgeneral character usuallyconsistof a pump" wh'i'ciiis operated by power yderived from the respective engine and which draws oil from lthe reservoir in the lower part of the crank case and discharges the same by means of conduits leading iii Avarious directions to the 4several bearings of the enginefand other parts which require lubrication. The pressure pipe 39 is connected with any suitable thev lubricating system of the engine whereby this piston is raised in the cylinder whenever the lubricatingpump is in operation but when the working of the lubricating pump is discontinued the piston 34; is relieved from pressure. When, therefore, the piston Set is raised by fluid pressure against theunder side of lthe saine the head 36 of t-lie piston engages the lower end of thevalvel stein 19 and holds the shut-off valve 18 iii its uppermost or fully opened position, `as indicated by the uppermost dotted line 18a in Fig. Q. When, hewevenpressure aga-inst thelower end 'ofthe piston ceases due to a discontinuance of the working of the lubricating pump when `thegras engine stops,` then the piston 3% descends by gravity into' its lowermost inoperative position aided by the resilience of the spring 3l which at the same time moves the shut-off valve downwardly into its closed position. between the piston 34' and the bore of the cylinder is made reasonably tighty by means ofpacking rings 40 arranged on the periph-k ery of thepiston so as to prevent an undueV amount of oil under' pressure'from passing from the lower end of the cylinder through the upper end thereof. Any oil, however, which does'escape to the upper end of the cylinder escapes vthrough an outlet 41 at the upper'end of the cylinder and conducted by a return pipi-42 to the crank case of the i engine or other source from which the lubricatingA pumpv draws its supply for transmission to the various parts of the engine which are to be lubricated, thereby keepii'igthis oil which is diverted from the lubricating system through the cylinder of the automatic 'shut-'off device constantly in circulation and' preventing the Asame from being wasted. In order to pieve'ntany oil `from escaping' through 'thew gmdewayb tween the upper head 291of Athe cylindervand erably constructed in the form The joint *iio the joint between the piston and cylinder to Athe 'pistonl rod" 19, thisguideway-ispref! if .ay smiling;

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salient face 27 is out of engagement from the lifting-collar 21 and the handle 28 isf arrested by engagement with the upperside of the head 29 and the piston is in its lowermost position in which its lug 37 engages with the lowerhead of the cylinder. Inthis position of the parts thefpassage of coinbustible gaseous fuel of fluid from the source of supply to the inlet of the gas inlet is positively cut off. For the purpose of starting the engine itis now first necessary to raise the lifting cam 2,5l from the position shown by full lines in Fig. 2 to the position shown by dotted lines in the same figure whereby the shut-olf valve will be raised to the position shown by dotted lines 181 in Fig. i2, whereby the port 1G the valve casing is opened and fuel gzs is permitted to iow from the source of supply to the inlet of the engine.

After the valve 18 has been thus raised by the salient' part 26 of the cam the tangential fiat locking face 27 of this cam engages with the under side of the lifting cam whereby this cam remains in its upper operative position and the valve is held in its open position without the necessity of the attendant holding the cam in this position by hand.

r1`he gas engine may now be started either by manual means or by a power starter such as are now` commonly employed for this purpose. After the engine has been started the oil circulating pump which is actuated by power derived from the engine produces a pressure in the lubricating system of the' engine on the outlet side of the pump. This pressure is in part conducted to the lower end of the cylinder 32 by means of the pressure pipe 39 whereby the piston 34 is raised and by engagement of the lower end of the valve stem 19 causes the valve 18 to be raised into its uppermost or fully open position, as indicated by dotted lines 18a and also causes the spring 31 to be compressed or placed under increased tension. During such lifting of the valve under the pressure derived from the lubricating system of the engine this valve is raised above the position where the same was lifted by Vthe lifting effect of the cam 25. then this occurs the cam 2:5- loses its hold on the lifting collar 21 and is thereby released from engagement therewith whereby the cam together-with its handle are permitted to drop automatically by gravity out of engagen'ientfrom the lifting collar 21 and into its lowermost position indicated by full lines in Fig. 2. The cam 25, is therefore, at this time moved downwardly and into such a position where the same is ont of the way and will not interfere with the free descent of the valvey 18 intoits'y i the valve is free to do s o. This freedom occurs whenever the vengine in which `this cut-ofi' device is incorporated ceases to operate, inasmuch as such a cessation terminates the generation of power ywhich operates the lubricating pump and, therefore, arrests the' `further generation of Dressure in the lubrirating syp piston '34 and due to the kabsence of this` em which is utilized to raise the pressure the piston 34 'and valve 18 are caused to descend and automatically shut off the flow of gas through the casing by engagement of the valve with its seat 17.

After this valve has engagedA this seat and shut-off the flow of gas from the 'source of supply to `the inlet" of the kgas engine'the latter can not be again started without first opening the shut-off valve 18 by deliberately raising the lifting cam 25, thereby preventingthe flow of gas in the source of supply to the engine and flooding the latter or the engine room in which the same `may be located if the attendant should fail to close the ordinary hand operated gas control valve which is usually provided on the engine for shutting off the finid gas supply and stopping the engine.

It will therefore be apparent that by means of this automatic shut-off device the liability of accumulating explosive gases within the engine when the same is at rest or in the spaces adjoining thereto is positively prevented and that any accidents or injuries which might result from the ignition of such accumulated gases are avoided and absolute safety in the operation of the engine byr gaseous fuels is assured.

le claim as our invention 1. An automatic shut-off device comprising a casing having a Huid inlet, a fluid outlet, and a valve seat between said inlet and outlet, a valve movable toward and from said seat and having a stem, a piston adapted to engage said valve stem and move the vvalve into an open position, a cylinder in which said piston slides and one end of which is adapted to be connected with a pressure source, and means for opening said valve manually comprising a collar arranged on said stem, and a cam adapted to engage said collar 'and having a handle for manipulating the same, said locking face being adapted to engage said collarupon turning the cam in one direction and said cam being released from said collar when pressure is applied to the underside of said piston.

2. An automatic shut-off device comprising a casing having a fluid inlet, a Huid outlet and a valve seat between said inlet and outlet, an inwardly closing valve movable toward andy from said seat, a pressure cylklowered or closed position undertheefl'ect of gravit-y aided by the spring'l 'whenever inder having a pressure inlet at one end and a. Waste outlet at the other end, a piston arrangedin said cylinder, a piston rod passing through said valve easing and said cylinder and connected at one end with said valve While its rother end is adapted to be loosely engaged by said piston, a spring arranged in said Cylinder and operating; on said. stein to move the valve in the direction for closing i it` and a earn operating on said stein and having ,a pressure inlet at one end and a Waste outlet at the other end, a pstonairanged in said cylinder, a piston rody passing i through said valve easing and said cylinder and connected at one end with vsaid valve while its other end is adapted to be .loosely engaged by said piston, a spring yarranged in said cylinder and operating on said stein to niove the valve in the direction for closing it, a Collar arang'ed on said stein between said easing and cylinder, and a earn pivotally mounted between said casing'y and cylinder and having a handle for shitting .the

saine manually, a cani face 'for engaging said collar andlii'ting'the valve from its seat, and a. locking face whereby said cani may be interlocked with said Collar for holdingr said valve in its open position.'

WrLLiAi/i F. BLAIR. VALENTINE D. KAUTH. 

